---
layout: wiki
title: InterWiki
updated: 2021-04-16 08:14
author: trac
default: true
toc: true
---

## Support for [InterWiki](/briareus/notes/InterWiki/) links

### Definition

An [InterWiki](/briareus/notes/InterWiki/) link can be used for referring to a Wiki page located in another Wiki system, and by extension, to any object located in any other Web application, provided a simple URL mapping can be done.

[InterWiki](/briareus/notes/InterWiki/) prefixes can even be used to introduce links to new protocols, such as \`tsvn:\` used by TortoiseSvn.

### Link Syntax

```
<target_wiki>(:<identifier>)+
```

The link is composed by the targeted Wiki (or system) name, followed by a colon, eg \`MeatBall:\`, followed by a page specification in the target.
Note that, as for [InterTrac](/briareus/notes/InterTrac/) prefixes, **[InterWiki](/briareus/notes/InterWiki/) prefixes are case insensitive**.

The target Wiki URL is looked up in the "[interwiki"\] section of [TracIni](/briareus/notes/TracIni/) and in the [InterMapTxt](/briareus/notes/InterMapTxt/) wiki page, modeled after MeatBall:[InterMapTxt](/briareus/notes/InterMapTxt/). If a prefix is defined in both the \`interwiki\` section and [InterMapTxt](/briareus/notes/InterMapTxt/), the \`interwiki\` section takes precedence.

In addition to traditional InterWiki links, where the target is simply *appended* to the URL, Trac supports parametric InterWiki URLs:
identifiers \`$1\`, \`$2\`, ... in the URL will be replaced by corresponding arguments.
The argument list is formed by splitting the page identifier using the ":" separator.

### "[interwiki"\]

Every option in the \`interwiki\` section in [TracIni](/briareus/notes/TracIni/) defines one [InterWiki](/briareus/notes/InterWiki/) prefix. The option name defines the prefix. The option value defines the URL, optionally followed by a description separated from the URL by whitespace. Parametric URLs are supported as well.

**Example:**

```ini
[interwiki]
MeatBall = http://www.usemod.com/cgi-bin/mb.pl?
PEP = http://www.python.org/peps/pep-$1.html Python Enhancement Proposal $1
tsvn = tsvn: Interact with TortoiseSvn
```

### Examples

For the following excerpt of the [InterMapTxt](/briareus/notes/InterMapTxt/) page:

```
= InterMapTxt =
== This is the place for defining InterWiki prefixes ==

Currently active prefixes: [[InterWiki]]

This page is modelled after the MeatBall:InterMapTxt page.
In addition, an optional comment is allowed after the mapping.
----
{{{
PEP      http://www.python.org/peps/pep-$1.html           # Python Enhancement Proposal $1
Trac-ML  http://thread.gmane.org/gmane.comp.version-control.subversion.trac.general/$1  # Message $1 in Trac Mailing List

tsvn     tsvn:                                            # Interact with TortoiseSvn
...
MeatBall http://www.usemod.com/cgi-bin/mb.pl?
MetaWiki http://sunir.org/apps/meta.pl?
MetaWikiPedia http://meta.wikipedia.org/notes/
MoinMoin http://moinmoin.wikiwikiweb.de/
...
}}}
```

Then,

- \`MoinMoin:InterWikiMap\` will be rendered as MoinMoin:InterWikiMap and the *title* for that link will be "InterWikiMap in MoinMoin".
- \`Trac-ML:4346\` will be rendered as Trac-ML:4346 and the *title* for that link will be "Message 4346 in Trac Mailing List".

### List of Active Prefixes

---

See also: [InterTrac](/briareus/notes/InterTrac/), [InterMapTxt](/briareus/notes/InterMapTxt/)